A computerized data bank has been established for cardiology patients in order to provide easy access to patient data for clinical and investigative purposes. Included in the data base is information from both outpatient and inpatient visits, as well as the identification of procedures and diagnoses generated at other institutions. The data includes symptom description; x-ray; ECG; catheterization; radionuclide; exercise stress test; ambulatory monitor and echocardiogram results; listing of current medications; and disposition of the patient. In addition, with the assistance of the "MIS" system, a printout of the catheterization results is generated for the medical records. Data accumulation was begun on January 1, 1978, and current and retroactive information has been entered on all of our patients. The data base of the Cardiology Branch and that of the NHLBI Surgical Branch were merged into one system, thus facilitating access to data on all patients with cardiovascular disease. Queries of the data base for clinical and research purposes have averaged about 20 per month. A summary of available "pertinent" clinical data is now obtained for each outpatient visit to the Surgery Clinic in order to make chart reviews easier at these visits. At the present time, there are 8,100 patients entered into the data base. Of these patients, approximately 5,000 have undergone some cardiac operation.